| 摘要 |
PURPOSE:To attain data transfer with simple constitution by providing register elements detecting and storing the presence or absence of request of transmission from each terminal in the lump onto a controller in response to on-off state of a transmission line, monitoring always the elements by the controller to reduce the waiting time of each terminal. CONSTITUTION:Plural terminal devices TM#0-TM#2 are connected to a terminal controller TMC to transfer information between a central processing unit and the terminal devices TM#0-TM#1 by the control of the central processing unit. The device TMC is provided with a microprocessor muCPU, a storage device ME, and a terminal control section TCT or the like and the control section TCT is provided with trigger registers TRGs impressed in response to an output of a receiving gate RV of the terminal devices TM#0-TM#2 by the number of the terminal devices TM#0-TM#2. Then, the state of the register TRG is monitored by the processor mu CPU, the request of transmission is detected, a polling signal is transmitted corresponding to the request, and data are transferred with he terminal TM receiving the polling signal. |
